public class leetcode278_第一个错误的版本 {

}

public class Solution extends VersionControl {
    public int firstBadVersion(int n) {
        if (n == 1 && isBadVersion(1)) {
            return 1;
        }
        int left = 1;
        int right = n;
        while(left < right) {
            int mid = left + (right - left) / 2;
            if (isBadVersion(mid)) {
                right = mid;
            } else {
                left = mid + 1;
            }
        }
        return left;
    }
}